Codeforces 476A - Dreamoon and Stairs Solution

  Solution in C++:

 ///La ilaha illellahu muhammadur rasulullah

///******Bismillahir-Rahmanir-Rahim******///

///AH Tonmoy

///Department of CSE,23rd batch

///Islamic University,Bangladesh

1. #include <bits/stdc++.h>
2. using namespace std;
3. int main()
4. {
5. long n,m,c;
6. cin>>n>>m;
7. if(n<m)
8. cout<<"-1"<<endl;
9. else
10. {
11. c=(n+1)/2;
12. while(c%m!=0)
13. c++;
14. }
15. cout<<c<<endl;
16. }